1950 Receiving Tube Substitution Guide Book H.A. Middleton Radio Electronics

Popular Tube Transistor Substitution Guide 1972

1974 Tube Substitution Guidebook-H.A. Middleton-Tube Caddy-Receiving Tubes

1970's Receving Tube books - RCA Receiving Tube Manual & Howard Sam's Tube Subst

Receiving Tube Substitution Guidebook First Supplement 1951

Vintage Servicing TV Receivers Vintage Manual Sylvania Electric 1950

Sams Tube Substitution Handbook Radio TV Tubes 1966 Booklet

TECHNICAL MANUAL SYLVANIA ELECTRONIC PRODUCTS 1955 RADIO TELEVISION PICTURE TUBE